Can anyone please help me by answering this question for me, its been puzzling me for 3 days.
I have recently started a new job as a test engineer. We use isolated oscilloscopes, and solder irons that run off mains. The other day I was testing a board and the scope and DC power supply with 15V, 5V and 6V rails were connected and supplying power to the PCB. Without disconnecting the PCB I touched up a dry solder joint using the solder iron.
Could this have damaged the board and blown a chip? What if the DC power supply was isolated using an isolated transformer, -could the solder iron still do damage?